It is difficult to squeeze a vast phenomenon like metal music in little more than 90 minutes, and this film is in fact biased (the director is a die-hard metal fan) and not very deep. For instance, death metal is covered superficially, and Christian metal (ever heard about Stryper?) not even mentioned. The interviews to fans are plain and uninteresting, in my opinion. The documentary has some very good parts though. Dee Snider gives a great interview and he oozes coolness and energy; we all feel sympathetic with his fight against the Congress' bigotry and political correctness. But the author of the film fails to mention that Snider is a Christian who does not do drugs nor gets drunk. Overall, the documentary lacks in-depth analyses, despite the author making clear since the beginning that he is an anthropologist; it is more the account of a fan who has fun interviewing big names. I borrowed the film so I cannot blame myself for wasting cash, and I enjoyed some parts of the documentary; but I cannot recommend buying the DVD.